Does anyone have any Nina Ottosson toys for their Chi's? I've been wanting to get Alfie a problem solving game like this as I think he would enjoy it but not sure what to get. I've been looking at Nine Ottosson's 'Dog Brick' interactive toy, which is on offer at Amazon at the mo. All her toys say they are suitable for any age or size of dog, but is that really the case? Can a Chihuahua manage to use these toys ok? All the pictures seem to be of Border Collies and large Jack Russels.